Is a graph Continuous and differentiable at a given point

In summary, the function f(x)={(2x-1)/Absolute value(2x-1) where x cannot equal (1/2) and 0 where x = (1/2) is not continuous at x = 1/2, as there is a jump in the graph at that point. Therefore, it is also not differentiable at x = 1/2, as every function that is differentiable must also be continuous.
  • #1
betsinda
12
0

Homework Statement



F
f(x)={(2x-1)/Absolute value(2x-1) x cannot equal (1/2)
{ 0 x = (1/2)

a) is f continuous at X = (1/2) explain
b) is f differentiable at x = (1/2) explain

Homework Equations



I have made the graph and x is a point at 1/2 but there is a jump. I have no idea how to start this.



The Attempt at a Solution

 
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  • #2
Drawing a graph is a good start. Can you describe what the graph looks like?
 
  • #3
the line from the left approaches (1/2) at +1 and restarts at (1/2) at -1. There is a single point at (0,1/2)
 
  • #4
sorry it continues to the right at -1
 
  • #5
betsinda said:
the line from the left approaches (1/2) at +1 and restarts at (1/2) at -1. There is a single point at (0,1/2)

No, none of this is right. The graph of this function is in three parts--two horizontal lines and a single point.

What is f(-1)? f(0)? f(1/2)? f(1)? f(2)? Plotting these points should give you an idea of what the graph of the function looks like.
 
  • #6
okay, I have fixed the graph. I have a line going from (1/2, 1) (1,1)(2,1) ect and a line going from (1/2,-1)(0,-1)(1,-1) ect, and a point at (1/2,0).

How do i determine if this is continuous at 1/2?
 
  • #7
One quibble. The line doesn't contain the point (1/2, -1). Does the graph look continuous at x = 1/2?
 
  • #8
I would say that the graph is not continuous at x=1/2 as that point does not connect to any other point on the graph.
 
  • #10
would it then be correct to say that x=1/2 is not differentiable as it is not continuous at that point?
 
  • #11
based on the fact that well every function is not differentiable, very function that is differentiable is continous. Or am I misunderstanding the concept?
 
  • #12
betsinda said:
would it then be correct to say that x=1/2 is not differentiable as it is not continuous at that point?
No. It doesn't make any sense to talk about a point or an x value being differentiable. You can say, though, that a function is continuous or differentiable at a point or at some x value.
 
  • #13
betsinda said:
based on the fact that well every function is not differentiable, very function that is differentiable is continous. Or am I misunderstanding the concept?
That is correct, so you are not misunderstanding the concept. I have made a couple of edits to what you wrote:
While not every function is differentiable, every function that is differentiable is continous.
 
  • #14
B) is f differentiable at x = (1/2) explain

So I could say that function is not differentiable at x=1/2 as the function is not not continuous?

Sorry for being a little slow I'm just trying to wrap my head around the concept. Thanks
 

1. What is the definition of continuity at a given point on a graph?

The definition of continuity at a given point on a graph is that the function is continuous if the limit of the function exists at that point and is equal to the value of the function at that point.

2. How can you tell if a graph is continuous at a given point?

You can tell if a graph is continuous at a given point by checking if there are any breaks, holes, or jumps in the graph at that point. If there are none, then the graph is considered to be continuous at that point.

3. What does it mean for a graph to be differentiable at a given point?

For a graph to be differentiable at a given point, it means that the slope of the graph at that point exists and is defined by the derivative of the function at that point.

4. How can you determine if a graph is differentiable at a given point?

You can determine if a graph is differentiable at a given point by checking if the graph is continuous at that point and if the tangent line at that point exists and is not vertical. If both of these conditions are met, then the graph is differentiable at that point.

5. Can a graph be continuous but not differentiable at a given point?

Yes, a graph can be continuous but not differentiable at a given point. This can happen if the graph has a sharp turn or corner at that point, which would make the tangent line undefined. However, if a graph is differentiable at a given point, it must also be continuous at that point.

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